Criminal Minds was a long-running criminal investigation procedural show that ended its original run in 2020. However, due to its recent increasing popularity on streaming sites such as Netflix, Paramount+ is set on making a new season with most of the original cast.

Related: 10 Hidden Details You Missed About Spencer Reid In Criminal Minds

To reach 15 seasons is a massive accomplishment in and of itself and the drama has produced some fantastic episodes in every season. These are often the episodes that break away from the usual formula and the IMDb scores show this, with the lowest-rated being 8.3/10!

Season 1: "Riding The Lightning" (8.5)

Mandy Patinkin in Criminal Minds

One of the best episodes of Season 1, "Riding The Lightning" was the first real Criminal Minds episode to break away from the whodunnit formula that the show often relied upon. Instead, it featured the BAU team interviewing the convicted husband and wife killers.

This was also quite a Gideon-centric episode, which capitalized on the character's then popularity. While chilling, the episode was also full of emotion, especially in the scenes between Gideon and Sarah Jean Mason. The twists and turns of the episode were also very intriguing.

Season 2: "Revelations" (8.9)

Spencer Reid being held hostage in Criminal Minds

"Revelations" is  one of the most intense episodes that the show has ever made. It also marked the first time an UnSub kidnapped a member of the BAU team. In the previous episode, Tobias Hankel, an extremely disturbed murderer, had kidnapped Spencer Reid.

"Revelations" focused on the fallout, which was tough to watch. Hankel's alter-ego insisted on torturing Reid and while the rest of the team found Reid before he was almost killed, it was clear that he'd already been through a lot. It was an amazing episode that definitely deserves its high ranking.

Season 3: "Penelope" (8.6)

Penelope Garcia holding a funny pen in Criminal Minds

The first Garcia-centric episode of the series, "Penelope" was absolutely shocking. In the closing moments of the previous episode, Penelope Garcia was shot by her date. Nobody saw it coming, which made it all the more terrifying.

Thankfully, Garcia survived the shooting but the UnSub got away. This episode further explored who Garcia was and it gave fans some utterly adorable moments between Garcia and Derek Morgan. This episode alone made Penelope Garcia one of the best characters in this season.

Season 4: "Mayhem" (8.5)

Hotchner looking after an injured woman after a car bomb exploded in Criminal Minds

Following on from the amazing aeason 3 finale, "Mayhem" is the first season premiere to have the highest IMDb rating of any season. The BAU team was investigating seemingly random killings that occurred in broad daylight. However, the truth was far worse than anyone had feared.

Related: 10 Hidden Details You Missed About Penelope Garcia In Criminal Minds

The murders were actually part of a brutal terrorist plot. The terrorists had hijacked an ambulance and rigged it up as a makeshift bomb. Morgan thankfully managed to drive the bomb away from the hospital but nobody was sure whether he himself had survived the blast.

Season 5: "100" (9.1)

Agent Hochner hugs his crying wife in Criminal Minds

As the title suggests, this episode was the 100th episode of Criminal Minds, which was an amazing accomplishment! However, this episode took it another step further with the return of George Foyet aka The Reaper, who broke into Hotchner's ex-wife's house and took her and her son hostage.

As if that wasn't bad enough, Foyet forced Hotch to listen as he taunted Haley and then killed her after she and Hotch shared a tearful goodbye. The whole team was shocked at losing someone close to them and Hotchner got his revenge in the most brutal way possible, making this one of Criminal Minds' most riveting episodes.

Season 6: "Lauren" (8.7)

Criminal Minds Lauren S6E18

Season 6 was a bit of a disted one. AJ Cook and Paget Brewster had been unceremoniously fired from the show; JJ left in the second episode and Emily left in the episode "Lauren."

Despite JJ's rushed exit, Emily got a slightly more decent send off. This was the culmination of the Ian Doyle storyline and it was intense. Doyle had kidnapped Emily and beaten and tortured her. Just as the BAU arrived, Doyle seemingly killed Emily, which was absolutely devastating for viewers.

Season 7: "Run" (8.5)

JJ, Emily and Morgan standing and discussing a case in Criminal Minds

The season 7 finale marked the second official departure of Emily Prentiss and it was just as exciting as the first. In a break from tradition, the two part finale featured the team on their day off, until a bank robbery gone horribly wrong forced them to come back to work.

Somehow, JJ's partner, Will, got caught up in the drama and ended up beaten down with a bomb tied to him. Emily got to him first and showed everyone what they would be missing once she was gone by singlehandedly saving Will's life in one of her best moments.

Season 8: "Zugzwang" (8.6)

Spencer Reid Receiving Phone Call In Zugzwang Criminal Minds.

Season 8 definitely felt different, as Emily was no longer part of the show. However, this season's most highly ranked episode was a Reid-centric one, which is always likely to please fans. Throughout the season, Reid had been involved with a mysterious woman who was in hiding from a vicious stalker.

In this episode, Maeve's stalker had finally found and kidnapped her, leaving Reid and the BAU desperate to find her before it was too late. Ultimately, there was no happy ending as the stalker opted to end her life and Maeve's rather than give the latter up.

Season 9: Demons (8.6)

Criminal Minds season 15 cast

Season 9 had a lot of good episodes, including the 200th episode of the series. However, the season finale was ranked highest by reviewers on IMDb. Another two part finale, the first half saw the BAU investigate what appeared to be a spate of religious killings.

Related: 10 Storylines Criminal Minds Dropped

However, in a massive twist, it was revealed that almost all of the sheriff's department were corrupt. The BAU team had essentially landed themselves in an extremely dangerous rat's nest and the danger was palpable, as it was impossible to tell who could be trusted.

Season 10: "Mr. Scratch" (8.7)

Mr. Scratch stares with wide eyes in Criminal Minds

Mr Scratch aka Peter Lewis is easily one of Criminal Minds' most twisted and creepy UnSubs, making this one of Criminal Minds' scariest episodes. In his debut episode, Scratch indirectly murdered three different people by proxy. What made this episode so unique was just how scary it was, even by Criminal Minds' standards.

It was more akin to a horror movie than a police procedural. The hallucinations of Mr Scratch by the victims were genuinely scary and even after Scratch was revealed, Peter Lewis was just so nauseatingly vile, it made for an unforgettable viewing experience.